The proposed research aims to continue the investigation of pair bond strength, parental care techniques, ontogeny, and territorial behavior of five mammalian species (lion tamarin, bush dog, crab-eating fox, maned wolf, elephant shrew) which are monogamous, but exhibit different levels of sociality. Research to date suggests that the degree of sociality is more important in predicting the degree of male parental investment, pair bond strength, sex role differences, and parent-juvenile conflict than the mating system. Further research is needed to confirm these findings and to isolate behavioral characteristics which are specific to monogamy. Comparisons of frequencies of agonistic and affiliative behaviors in pairs with bonds of different durations will permit a more exact definition of pair bond strength. Male and female time budgets during the rearing of offspring, and sex differences in scent-marking and vocalizations, will permit a comparison of adult sex roles. Detailed observations on juveniles prior to and during puberty will suggest the causes of dispersal and the mechanisms whereby a nuclear family is maintained. The development of sex roles will be examined by observing preferences in parental care by adults and juveniles. An experimental analysis of dominance relations within pairs will suggest whether female dominance is a major characteristic of monogamous mammals. The isolation of characteristics which do not vary with sociality in monogamous mammals will contribute to our understanding of the evolution of monogamy as a reproductive strategy.